The structure and neurobiology of repetitive and restricted behavior in the autism spectrum

Abstract

Autism spectrum disorder (ASD) is a pervasive and relatively common childhood disorder. It is currently understood that it is a spectrum of disorder, characterized by a very heterogeneous etiology. One of the core components of ASD is restricted and repetitive behaviors (RRBs). This is a broad class of behaviors characterized by repetition and rigidity and is separable from social and communication deficits in ASD. A wide variety of instruments are currently being used to measure RRBs and various models are employed to characterize this heterogeneous category of behavior. Research on the neurobiology of RRBs has revealed a cortico-basal ganglia system. In this system, direct and indirect pathways involved in sensorimotor, associative and limbic loops, balance different behaviors. This balance can be perturbed by a wide variety of genes and neurotransmitters, resulting in various RRBs. Studying RRB has already revealed much in various areas of research, and has led to novel ASD candidate genes and information on the neurobiology of ASD. The possible impact of improved characterization of RRB on ASD research, diagnosis and treatment is discussed.